Spectroscopic investigations on thin adhesive layers in multi-material laminates

Area of Science:

• Materials Science
• Spectroscopy
• Polymer Science

Background:

• Polymeric photovoltaic backsheets utilize thin adhesive layers for structural integrity.
• Environmental factors like weathering and aging can degrade these adhesive layers.
• Accurate visualization techniques are crucial for assessing layer integrity and performance.

Purpose of the Study:

• To evaluate spectroscopic methods for visualizing thin adhesive layers in photovoltaic backsheets.
• To investigate the impact of aging and weathering on adhesive layer uniformity and thickness.
• To compare the effectiveness of Raman linescans, Raman imaging, and ATR FT-IR imaging.

Main Methods:

• Raman linescans
• Raman imaging
• Attenuated total reflection Fourier transform infrared spectroscopy (ATR FT-IR) imaging
• Analysis of original, weathered, and artificially aged multilayer laminates.

Main Results:

• All three spectroscopic methods successfully detected and visualized thin adhesive layers (3-6 μm).
• Raman linescans provided only qualitative data due to non-uniform layer thickness.
• Raman imaging offered more comprehensive data on uniformity and evenness compared to linescans.
• ATR FT-IR imaging visualized layers but faced resolution limits.
• Raman imaging and ATR FT-IR imaging showed consistent results regarding aging impacts.

Conclusions:

• Raman imaging and ATR FT-IR imaging are suitable for visualizing thin adhesive layers in photovoltaic backsheets.
• Spectroscopic imaging provides superior insights into layer uniformity and degradation compared to linescans.
• Environmental aging significantly affects adhesive layer integrity, detectable by advanced spectroscopic techniques.